03/08/87

Brief history. I got this car last month and tuned it up the best I know how, I'd say all the minor stuff anyone can do-I did. Then after I cranked with the hood up, I did a once over and saw the trans bolts were loose. I freaked and tried to take the hood off to get to them and broke the washer hose plastic clip. Not a big deal, right? Then I called for a tow and took it in to Mazda, where they tightened them and did an inspection and replaced the ball joints, tie-rods, f/r brake pads and a clutch master cylinder. I got it back today and got two problems (5 beep steering sensor and the idle)and a lot of worries (did they change the transmission fluid).


Before the car went in, the idle was great as I had reinstalled the cold start plunger, where it was disconnected and hanging by one bolt. The idle was 3000 at startup, 1500 briefly, then settled to 750. Now I got it back, it goes to maybe 3k, then to around 2k, then alternates between 1400 and 1600. Although it doesn't sound like much, its very noticable and probably not very good for the car.

While I do have a FSM and access to here, I don't have a whole lot of knowledge or tools and the dealer put the hurt on the funds so its DIY time. I do feel kind of spoiled to have gotten a great example where 'the pros' buy broken down heaps and restore them beyond factory.

I don't have a timing gun or know how to use one. I've searched and the TPS seems likely out of adjustment or w/e. According to the workorder at Mazda, they didn't deal with the engine, but did put a new battery box in. From past experiences, after disconnecting the battery, I thought the computer needed time to adjust itself and that could be the reason for a bouncing idle. Maybe I'm jumping the gun by posting, but I just want to get headed in the right way.

87 NA 5spd.

Jpk3200

Might want to check these out. I'm not sure if that's your problem, but someone else on the forum was having a 1400-1600 idle surge problem; they adjusted the cam adjusting screw and fast idle cam screw, and it fixed their problem.

NoDOHC

Welcome to the club...

Not just the rx7club, but the RX7 Club (you know, the one where everyone has Idle issues.)

First I would look if the dealer may have broken an old brittle vacuum line while tightening the transmission bolts.

After that, your best bet is probably to follow the procedure for setting the TPS, Idle, Timing, Idle air/fuel ratio (only if screw looks like it has been tampered with). I would set them in that order.

A timing light is super-simple. You plug it on to the battery and the leading plug wire for the front rotor and aim it at the front pulley (looking for the little mark).
I would recommend getting on from advance or autozone and then returning it when finished. I also like to run my car with the timing advanced 15° ahead of stock.

You should use a voltmeter or two lights to set the tps. The exact procedure is in the FSM.

If you never touch the A/F adjust screw, you can adjust all the sensors by ear. I would not recommend it until you have followed the factory procedure though, that can also lead to serious issues.

03/08/87

When the a/c is on it idles at a steady 1400.




I just wonder why it is huff and puffing without the load from the a/c.

03/08/87

We messed with two screws. The idle screw under the blind cap and the other screw that is easily accessable.. The cam screw maybe. We just dove in and didn't follow FSM procedure, so the idle never went down because we didn't have the jumper to the terminals to the initial set coupler.

I don't know what we did or why it ever was out of adjustment since the dealer did no work to it that I know of. However, the surging is all but gone. The idle is not dead set and does surge ever so slightly, but is much smoother than before.


I'll check through the procedures in the FSM and try to fine tune it by adjusting the aforementioned fast idle adjusting screw and the cam adjusting screw. thx